The invention relates to gas turbines and more particularly to a Tesla-type spiral flow turbine having provision for turbine blade cooling and gas regeneration.
The basic Tesla turbine is described in Tesla U.S. Pat. No. 1,061,206. Combustion gases or other pressurized working fluids enter the turbine chamber through a nozzle directed generally tangentially to the outer periphery of a plurality of spaced apart flat disc-like turbine blades. The fluid travels in an inwardly spiralling path while effecting the rotation of the turbine blades, and is axially exhausted from openings defined in the blades close to the center of rotation. The efficiency of this type turbine lies in its elimination of sudden changes of the velocity and direction of movement of the fluid which generally occur with turbines having conventional vanes or blades.
Gas regenerators, i.e., means for utilizing the heat present in the exhaust gases on a turbine to heat intake air for combustion, are well known. The regenerators, however, are generally external to the turbine and merely effect a heat exchange between the gases finally exhausted from the turbine and intake air for combustion. See, for example, U.S. Pat. No. 2,784,552. While such a gas regeneration system does reclaim some heat energy from the exhaust gases, it does not utilize heat exchange in a Tesla-type turbine to the extent of the present invention described below.